A prior art type of vi control for inking units is known from DE-AS 1,248,682. As disclosed in this reference, a forked lever is connected to a link and the link is connected to the cam follower lever such that the place of articulation is adjustable. This construction facilitates accurate distance (stroke) adjustment of the vibrator. However, substantial impacts also occur in operation at the critical point in the oscillating movement of the vibrator--i.e., when the vibrator engages with and disengages from the ink ductor and the distributing rollers. Another disadvantage is that as vibrator diameter varies, for example, because of wear, the times of engagement and, therefore, the widths of the vibrator-transferred ink strips vary.
It is also known from DE-OS 2,105,622 to adjust the engagement of the vibrator with the ink ductor and with the distributing roller by adjustable abutments. In this arrangement, since the abutments, which are rigidly disposed on the press, cooperate with rubber blocks on a rocking lever, a resilient engagement with adjustment is possible but there can be no pause in vibrator movement before it engages with either of the other rolls. Therefore, the disadvantages described above also occur in this case--i.e., the vibrator strikes the ductor too fast and the engagement times and thus the width of the ink strips vary because of wear.